Spatial Truss

ABSTRACT

A truss includes a first cap, a second cap, a core member, at least two struts, and a fastening member securing the struts to the core member between the first cap and the second cap. The struts are rotatably attached to the core member between the first cap and the second cap of an angle between 15° and 180°.

BACKGROUND

Space frames are structures with regular repetitions of standard modules. A conventional space frame is typically made up of multiple repeated modules of interlocking struts, configured in a geometric pattern. A connector joint is usually used to fix the geometry of each module, with an array of openings that allows struts to be connected at predefined angles, examples of which can be found at FIG. 1 of U.S. Pat. No. 4,676,043 and FIG. 4 of U.S. Pat. No. 4,259,821. However, these existing designs allow for struts to be joined only at pre-defined orientations, and are thus capable of forming only regular geometric space frame structures.

For space frames that require struts to be connected at varying orientations, special hinged connector joints must be included. For example, a hinged connector joint may have metal plates welded to a cylindrical core, and strut members are then connected to hinges on the metal plates, allowing for adjustments of the strut tilt, an example of which can be found at FIG. 4A of U.S. Pat. No. 5,125,206. The process for manufacturing the connector joints can be complicated. The orientations of the metal plates are usually predefined, which limits the design flexibility of the system. Moreover, the strut members connecting to the same joint are not usually in alignment, which complicates the strut member length calculation, especially when the space frame geometry is irregular.

A spatial truss is a three-dimensional structure having regular or irregular geometry. Unlike a space frame, a spatial truss can have struts of different lengths connected together at different angles. The connector joints for use with multiple struts of different lengths and/or orientations are typically customized and specially manufactured.

A common way to construct a spatial truss is to have individual struts cut at pre-measured lengths, and then joined or welded together at the appropriate angles on-site. However, because each strut member and connector joint would have to be custom-made, this method makes it difficult for mass production, quality assurance, and stock management.

It is desirable to develop a spatial truss system that enables a variable number of struts to be connected to the connector joint at various angles, without requiring the connector joint to be custom made. It is also desirable to have a spatial truss system that is simple to manufacture and is convenient to assemble.

BRIEF SUMMARY

According to one aspect, a truss may include a first cap, a second cap, a core member, at least two struts, and a fastening member securing the struts to the core member between the first cap and the second cap. The struts may be rotatably attached to the core member between the first cap and the second cap of an angle between 15° and 180°.

According to another aspect, a truss system may include a first strut rotatably attached to a first connector joint and a second connector joint, a second strut rotatably attached to the first connector joint and a third connector joint. The first and second struts may be rotatably attached to the first connector joint between an angle of 15° and 180°.

According to a further aspect, a method of making a truss may include positioning a core member between a first cap and a second cap, positioning at least two struts on the core member at the desired directions, fastening the struts to the core member between the first and second caps using a fastening member. The struts may be rotatably attached to the core member between the first cap and the second cap between an angle of 15° and 180° and include a tilt angle from −30° to +30°.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an axonometric view of an elaborated example of a connector joint securing four struts.

FIG. 2 depicts the front view of FIG. 1 showing the positioning angles between adjacent struts.

FIG. 3A depicts a partial cross-sectional view of FIG. 2 along plane T.

FIG. 3B depicts a cross-sectional view of FIG. 2

FIG. 4A depicts a cross-sectional view of a simplified example of a connector joint having a single strut at a nominal position.

FIG. 4B depicts the same view as FIG. 4A showing the position of a strut at a maximum tilt angle.

FIG. 5 depicts an axonometric view of multiple struts with a partial dish member to reduce the positioning angle between adjacent struts.

FIG. 6 depicts an axonometric view of an example of a full dish member of a single strut member.

FIG. 7 depicts an embodiment of a truss system.

FIG. 8 depicts an embodiment of a geometric structure formed by the truss system.

DETAILED DESCRIPTION

Reference will now be made in detail to a particular embodiment of the invention, examples of which are also provided in the following description. Exemplary embodiments of the invention are described in detail, although it will be apparent to those skilled in the relevant art that some features that are not particularly important to an understanding of the invention may not be shown for the sake of clarity.

Furthermore, it should be understood that the invention is not limited to the precise embodiments described below, and that various changes and modifications thereof may be effected by one skilled in the art without departing from the spirit or scope of the invention. For example, elements and/or features of different illustrative embodiments may be combined with each other and/or substituted for each other within the scope of this disclosure and appended claims. In addition, improvements and modifications which may become apparent to persons of ordinary skill in the art after reading this disclosure, the drawings, and the appended claims are deemed within the spirit and scope of the present invention.

A truss 10 may include two or more struts 12 or 13 rotatably connected to a connector joint 14. For example, four struts 12 or 13 may be connected to the connector joint 14, as depicted in FIGS. 1 and 2. The connector joint 14 may be configured to enable a strut 12 or 13 to be positioned at any angle k with respect to another strut 12 or 13, from an angle of 15° to 180° and a tilt angle a of from −30° to +30°, as depicted in FIG. 4A.

Struts

The strut 12 may be a single piece with a partial dish member 34 at one or both ends, as depicted in FIG. 5, or with a full dish member 36 at one or both ends, as depicted in FIG. 6. Alternatively, the strut 13 may be assembled together by a body member 16 and a head member 18 removably attached to the body member 16, as depicted in FIGS. 1 and 2. The strut 13 may also include a partial dish member 34 or a full dish member 36 at one or both ends.

The dish member 34 or 36 is configured to be secured to the connector joint 14 at any number of positions while being adjustable to any angle k, as depicted in FIG. 2. The full dish feature 36 may include an inner concave spherical surface and an outer convex spherical surface concentric to each other, as depicted in FIG. 6. The partial dish feature 34 may similarly include an inner concave spherical surface and an outer convex spherical surface concentric to each other but with the side portions removed, as depicted in FIG. 5. The partial dish feature 34 may reduce the positioning angle k between adjacent struts and enable a larger number of struts to be simultaneously positioned within the connector joint 14. As will be seen, a number of struts 12 or 13 connected together in this manner may form a two-dimensional or three-dimensional structure.

The head member 18 and body member 16 may include mating fastening interface 20 configured to fasten the head member 18 to the body member 16, and to allow the body member 16 to be separated from the head member 18. The ability to separate the body member 16 from the head member 18 allows body members 16 of different shapes and lengths to be replaced, according to the loading and geometry requirements of a given truss 10. Moreover, the ability to substitute a different body member 16 while the head members 18 are connected to the connector joint 14 provides added flexibility and convenience to the user, while the truss 10 is being assembled or modified.

The shape of the head member 18 may be chosen depending upon the manufacturing process or planned load to be supported by the truss 10, and may take the shape of a rectangle, a cone, a cylinder, or any other shapes known to one of ordinary skill in the art. The length of the struts 12 or 13 may vary based on the overall architectural structural geometry and the loading requirement of the truss 10, as determined by one of ordinary skill in the art. Depending on required loading, manufacturing process, and appearance aesthetics, both the body member 16 and head member 18 may include materials such as polymers, metals, or wood. Examples of polymers include acrylonitrile butadiene styrene (ABS), polypropylene (PP), and combinations thereof. Examples of metals include aluminum, steel and brass, and combinations thereof.

Connector Joints

The connector joint 14 may include a first cap 24, a second cap 26, and a core member 28 fastened together by a fastening member 30 or integrated fastener in a second cap 26, as depicted in FIGS. 4A and 4B. The fastening member 30 may be configured to position the core member 28 between the first cap 24 and the second cap 26, and to secure the dish member 34 or 36 within a cavity 32 in the connector joint 14. The connector joint 14 may include the cavity 32 between the core member 28 and the first cap 24, and between the core member 28 and the second cap 26. Examples of the fastening member 30 include a bolt, a hex socket screw, and any other fastening devices known to one skilled in the art. In one example, the hex socket screw may be inserted through the second cap 26 and the core member 28, and fastened into the thread hole 25 of first cap 24. In another example, the first cap 24 and the second cap 26 may include a common channel through which a fastening member may pass to fasten the connector joint 14 with an additional nut beyond first cap 24.

The strut 12 or 13 may be connected to the connector joint 14 by positioning the dish member 34 or 36 within the cavity 32 between the first cap 24 and the second cap 26, and biasing the dish member 34 or 36 against the core member 28. The biasing may include tightening the fastening member 30 when the dish member 34 or 36 is at a given position. For example, the strut 12 may be connected at a first position, as depicted in FIG. 4A, or a second position, as depicted in FIG. 4B.

The relationship of the strut 12 or 13 with the first cap 24 and second cap 26 at the connector joint 14 may be described by several designing parameters, as depicted in FIG. 4A. The connector joint 14 may include a maximum tilt angle a by which the strut 12 or 13 may be tilted about the core member 28. The tilt angle a may range from −30° to +30°. The connector joint 14 may also include a clearance angle c for tilting the strut 12 or 13, which should be greater than or equal to the maximum tilt angle a. The connector joint 14 may also include a dish member span angle b to ensure that the strut 12 or 13 overlaps or remain in contact with the cap 24 or 26 when the strut 12 or 13 is at the maximum tilt. The dish member span angle b should be greater than or equal to two times the maximum tilt angle a. The connector joint 14 may also include a clearance for strut member e for designing the geometry of the first cap 24 and second cap 26, which should be greater than or equal to half of a strut diameter d.

FIG. 4B shows when the strut 12 or 13 is tilted to the maximum tilt angle a and rested against the first cap 24. FIG. 4B also shows that the dish member 34 or 36 would have to maintain contact with the second cap 26 so as to prevent the strut 12 or 13 from falling out of the connector joint 14.

The core member 28 may be connected to two or more dish members 34 or 36 of the struts. In one example, the core member 28 is connected to four dish members 34. In another example, the core member 28 is connected to six dish members 34. Other numbers of struts 12 or 13 may be connected to the core member 28, depending on the loading and geometry requirements of the truss 10, as determined by one of ordinary skill in the art.

The first cap 24, the second cap 26, and the core member 28 may include materials such as polymers, metals, or wood. Examples of polymers include ABS, PP, and combinations thereof. Examples of metals include aluminum, steel, brass, and combinations thereof.

Connector Joint Variation

Another embodiment of the connector joint 40 may include a first cap 42, a second cap 44, a core member 46, and a fastening member 48, as depicted in FIGS. 3A and 3B. Similar to the fastening member 30, the fastening member 48 may be configured to position the core member 46 between the first cap 42 and the second cap 44, and to secure the dish member 34 or 36 to the connector joint 40. Examples of the fastening member 48 include a bolt, a hex socket screw, and any other fastening devices known to one skilled in the art. For example, the hex socket screw may be inserted through the second cap 44 and the core member 46, and fastened into the first cap 42. The core member 46 may include a sleeve on both ends facing the first cap 42 and second cap 44 to reduce deformation.

The connector joint 40 may include a cavity 50 between the core member 46 and the first cap 42, and between the core member 46 and the second cap 44. The strut 12 or 13 may be connected to the connector joint 40 by positioning the dish member 34 or 36 within the cavity 50 between the first cap 42 and the second cap 44, and biasing against the core member 46. The biasing may include tightening the fastening member 48 when the dish member 34 or 36 is at a given position. For example, the strut 13 may be connected at a first position, as depicted in FIG. 3A or a second position as in FIG. 3B.

The core member 46 may be connected to two or more dish members 34 or 36 of the struts. In one example, the core member 46 is connected to four dish members 34. In another example, the core member 46 is connected to six dish members 34. Other numbers of struts 12 or 13 may be connected to the core member 46, depending on the loading and geometry requirements of the truss 10, as determined by one of ordinary skill in the art.

The first cap 42, the second cap 44, and the core member 46 may include materials such as polymers, metals, or wood. Examples of polymers include ABS, PP, and combinations thereof. Examples of metals include aluminum, steel, brass, and combinations thereof.

Spatial Freeform Truss

When two or more struts 12 or 13 are connected to the connector joint 14 or 40, there are positioning angles k created among the struts 12 or 13. The angle between any two of the struts 12 or 13 may vary from an angle of 15° to 180°. The exact positioning angles of the struts 12 or 13 at a given connector joint 14 or 40, the number of struts 12 or 13, and the length of the struts 12 or 13 may depend upon the desired geometry of the truss system 10. The diameter of the struts 12 or 13, the geometry of the head member 18 or dish member 34 or 36, the diameter of the core member 28 or 46, the size of the first cap 24 or 42, and the size of the second cap 26 or 44 may depend on the loading and aesthetic design of the truss 10 according to one of ordinary skill in the art.

The positioning angle of the struts 12 or 13 at the connector joint 14 or 40 may be freely adjusted around the circumference of the connector joint 14 or 40 along the x-y plane of FIG. 1 by loosening the fastening member 30 or 48 of the connector joint 14 or 40. The number of struts 12 or 13 at the connector joint 14 or 40 may also be freely added or removed by loosening the fastening member 30 or 48. Therefore, the truss 10 enables two or more struts 12 or 13 to be adjustably connected at the connector joint 14 or 40 at any desired direction, without requiring the use of a customized connector joint. The ability of free movement of the struts 12 or 13 allows the creation of freeform spatial structures of the truss 10.

Method

A method of making a truss may include positioning a core member between a first cap and a second cap, positioning at least two struts on the core member at the desired locations, and fastening the struts to the core member between the first and second caps using a fastening member. The struts may be rotatably attached to the core member between the first cap and the second cap between an angle of 15° and 180°, and may be tilted between an angle of −30° and +30°.

Spatial Truss System

Multiple struts and connector joints may be connected together by connector joints 14 or 40 to form a spatial truss system, as depicted in FIG. 7. A truss system may include a first strut rotatably attached to a first connector joint and a second connector joint, and a second strut rotatably attached to the first connector joint and a third connector joint. The first and second struts may be rotatably attached to the first connector joint between an angle of 15° and 180°. In one example, the truss system may include a third strut rotatably attached to the first connector joint and a fourth connector joint to form a tree-like branching structure. The first, second, and third struts may be rotatably attached to the first connector joint between an angle of 15° and 180°. In another example, the truss system may include a third strut rotatably attached to the second connector joint and the third connector joint to form a rigid triangle. In a further example, the truss system may include a third strut rotatably attached to the second connector joint and a fourth connector joint to form an open U-shape frame.

An example of a geometric structure formed from multiple truss systems is depicted in FIG. 8. The flexibility of including a varying number and angle of the struts 12 or 13 at the connector joint 14 or 40 enables a variety of geometric structures to be made.

While the trusses and methods have been described, it should be understood that the system is not so limited, and modifications may be made. The scope of the trusses and methods is defined by the appended claims, and all devices and methods that come within the meaning of the claims, either literally or by equivalence, are intended to be embraced therein. 

1. A truss, comprising: a first cap; a second cap; a core member; at least two struts; and a fastening member securing said struts to said core member between said first cap and said second cap, wherein said struts are rotatably attached to said core member between said first cap and said second cap of an angle between 15° and 180°.
 2. The truss of claim 1, wherein said struts independently comprise a tilt angle of between −30° and 30°.
 3. The truss of claim 2, further comprising a clearance angle for tilting said struts, wherein said clearance angle is greater than or equal to said tilt angle.
 4. The truss of claim 2, further comprising a dish member span angle, wherein said span angle is greater than or equal to two times of said tilt angle.
 5. The truss of claim 1, wherein said struts independently comprise a strut diameter.
 6. The trust of claim 5, further comprising a clearance for said struts, wherein said clearance is greater than or equal to half of said strut diameter.
 7. The truss of claim 1, wherein said struts comprise a dish member at one end.
 8. The truss of claim 7, wherein said dish member comprises a full dish member.
 9. The truss of claim 7, wherein said dish member comprises a partial dish member.
 10. The truss of claim 7, wherein said dish member is positioned in a cavity between said core member and said first or second cap.
 11. The truss of claim 1, wherein said struts comprise a body member and a head member removably attached to said head member, and wherein the head member is rotatably attached to said core member.
 12. The truss of claim 11, wherein said struts comprise a dish member at one end.
 13. The truss of claim 11, wherein said head member comprises a mating interface configured to fasten said body member to said head member.
 14. The truss of claim 11, wherein said head member comprises a rectangular, a conical, or a cylindrical shape.
 15. The truss of claim 11, wherein said head member and said body member independently comprise polymer, metal, or wood materials.
 16. The truss of claim 15, wherein said head member and said body member independently comprise a polymer material selected from the group consisting of acrylonitrile butadiene styrene (ABS), polypropylene (PP), and combinations thereof.
 17. The truss of claim 15, wherein said head member and said body member independently comprise a metal material selected from the group consisting of aluminum, steel, brass, and combinations thereof.
 18. The truss of claim 1, wherein said fastening member comprises a bolt or a hex socket screw.
 19. A truss system, comprising: a first strut rotatably attached to a first connector joint and a second connector joint; a second strut rotatably attached to said first connector joint and a third connector joint; wherein said first and second struts are rotatably attached to said first connector joint between an angle of 15° and 180°.
 20. A method of making a truss, comprising. positioning a core member between a first cap and a second cap; positioning at least two struts on said core member at the desired locations; fastening said struts to said core member between said first and second caps using a fastening member, wherein said struts are rotatably attached to said core member between said first cap and said second cap between an angle of 15° and 180°, and comprise a tilt angle from −30° to +30°. 